Die drawing of clad rod or wire



March 12, 1963 E. FLEISCHMANN ETAL 3,080,962

I DIE DRAWING OF cum ROD 0R WIRE Filed June 12, 1959 INVENTORS ErnstFleischmonn 8 Leslie 0. Whitne %M@ drawing thereof.

United States Patent 3,080,962 DIE DRAWING F CLAD ROD 0R WIRE ErnstFlcischmann, Clairton, and Leslie C. Whitney,

Forest Hills, Pa, assiguors to Copperweld Steel Company, Pittsburgh,Pa., a corporation of Pennsylvania Filed June 12, 1959, Ser. No. 819,9712 Claims. (Cl. 205-16) This invention relates to apparatus and methodfor reducing the diameter of clad rods and wires by the die Moreparticularly, this invention pertains to dry die drawing of aluminumclad steel rod and wire at practicable production speeds.

The instant invention'make practical the dry die drawing of clad rod andwire such as Alumoweld aluminum clad steel rod and wire at productionspeeds without scratching, scoring or gelling the cladding surface andwithout stripping or upsetting such cladding and with concurrentreduction of cladding and core despite the thickness of cladding and itsrelative softness and Weakness when compared with the core as in thecase of such aluminum clad rod and wire, such as that producible by thesystem disclosed in United States patent application Serial No. 773,125filed June 16, 1958.

-Other objects, features and advantages of thi inven- .tion will beapparent from the following description and of FIGURE 3; and

FIGURE 5 is a view in section taken along line V-V of FIGURE 4 toillustrate a section through a triple die embodiment of this invention.

Referring to the drawings, a machine is provided with a trunnioned dieholder 11, a die assembly embodiment 12 of this invention for dry diedrawing of a clad rod or wire 13 such as the aluminum clad steel rod orwire named above and a capstan 14 having wraps of the reduced rod orwire 13a therearound for traction and cooling. In the illustration, themachine is a so-ealled onehole machine and the wraps on capstan 14 as itrevolves move up onto coiling posts 15 from which the coil of reducedwire 13a is periodically removed. The wraps on capstan 14- may, instead,be conducted through one or more further die drawing stations or holesin continuous succession for the reduction thereof in successive stagesutilizing conventional automatic multihole wire drawing equipment.

Die holder 11 is pivotally supported about horizontal pivots 16 bybrackets 16a and comprises an open-top box with a cleamout opening inthe bottom thereof normally closed by a pipe plug 17. The front of thebox is pro vided with an axial opening 18 in which a guide disc 19 maybe seated. Disc 19 may be made of a material like nylon with a centralopening 20 therethrough for the rod or wire 13, hereinafter called wire,which is pulled in the direction of arrow 21 by the rotation of capstan14 at a selected linear speed by power means (not shown) for machine 10.The capstan 14- is preferably cooled interiorly by water or otherwiseand air blasts may be provided around its exterior to sweep its wraps ofdrawn Wire to cool said wire, particularly when the cladding may be arelatively soft metal like aluminum.

At the front of die holder- 11 there is a generally 'U-shaped die clamp22 bolted thereto. Clamp 22 is provided with vertical guide grooves 23opposed to one anice other and a swingable locking strap 24 to be closedto lock a die base 25 in place after it has been slid into place inholder 11, the base 25 being provided with vertical side projectionswhich fit in grooves 23. Base 25 is provided with a drilled and tappedopening 26 in which die assembly 12 is rigidly fixed in coaxial positionrelative to the axis of the path of movement of the wire, which isreduced when it is drawn through die assembly 12. The reduced wire 13amoves on through opening 27 in die holder 11 and engages capstan 14initially at the bottom of the tier of wraps therearound.

Die assembly 12 in the illustrated embodiment comprised a hollow diemount 28 having a threaded end 29 which screws tightly into the opening26 in base 25 to rigidly hold the mount without movement during diedrawing operations. The other end 30 of mount 28 is also threaded forengagement by an annular retainer nut 31. Further, a boss 32 around themiddle of mount 28 has its exterior surfaces in the form of a square forengagement by 'a spanner wrench whenever mount 28 is to be insertedinto, or removed from, base 25. Mount 28 is provided with an axialcircular bore 33 communicating at the exit end thereof with a smallerdiameter opening 34 coaxial with opening 27, the axis and direction ofmovement of the clad wire therethrough being represented by the arrows35.

Die assembly 12 utilizes a front or entrance die 36, an intermediate die37, which dies 36 and 37 act as pressure dams, and a reduction ordrawing die 38, although the device of this invention is operative alsowith but one pres sure dam die and one drawing die. Each die has anoutside cylindrical surface which slidably and closely fits in bore 33.In addition, the front face of die 36 projects enough to engage theopposed face of nut 31 to clamp the dies in the mount 28. Such faces arepreferably provided with a fine true finish in the mating plane at 39,as is the case also at the rear plane 40 defined by the rear face ofreduction die 38 and the bot-tom of bore 33 around opening 34. Thedirectly opposed adjoining faces between each pair of dies are providedwith annular grooves'41 which 'have a very superiorfinish to engage theflat faces, with like superior finishes, of sealing rings '42 which maybe made of hardened steel, or other sealing means may be providedbetween the dies so that the pass-age therethrough and through openings43 in sealing rings constitutes an elongated high pressure spacepursuant to which continuous, cold, dry-die drawing is obtainable onclad Wire without impairment of the relation between cladding and coreand with proportionate reduction of such cladding and core, even thoughsuch two metals may be greatly dissimilar in their respectiveproperties.

In a die drawing operation of this invention, an aluminum clad rod 13moving toward die assembly 12 is dabbed or wiped with a carrier, such ascastor oil or a suitable dag, to provide some surface tackiness. It

may be done manually or from a dabber supply 44 with a rotating wiper45, or the wiping may be continuous with preferably a sparingapplication of such carrier material. The wire 13 then passes into thebox of die holder 11 and receives a coating of finely powderedconventional soap lubricant represented by a chain line 46 (FIGURE 4),which is compatible with the cladding metal on the clad wire beingdrawn, before entering a wide angle opening 47 through the center ofretainer nut 31. The width of opening 47 and the comparatively shortlength of die 36 facilitate the feeding of clad wire 13 from a coil intoassembly 12 without previous straightening. The clad wire 13 is of adiameter which is somewhat less than the diameter of the bearing 48 ofdie 36 where central opening 49 through that die is at its narrowest.The same relation exists between the outside diameter of clad rod 13 andbearing 50 of die 37 except that the clearance for the clad wire inbearing 50 preferably is somewhat less. As a consequence, considerablepressure appears to build up in the central space between bearing 48 andpassage 51 in the intermediate die 37 with perhaps a still greaterpressure between bearing 50 and the approach angle 53 of reduction die38 which promotes, in the manner of an extrusion effect, the drawing ofaluminum cladding so that it takes place in accordance with theelongation of the core while the clad wire is being drawn, withoutscoring, stripping or upsetting of that aluminum cladding by bearing 54in the reduction die 38. In the initiation of such an operation, theleading end of the clad rod to be drawn is pointed by tapering of atleast the cladding in the direction of intended movement for severalinches to facilitate the commencement of such a die drawing operation.As the composite wire passes through the die box, the conventional soaplubricant adheres to the surface of the clad wire. The continuouscarrying of soap lubricant into the die assembly builds up a very highpressure in this assembly until the quantity of lubricant brought intothe die passages substantially equals the amount of lubricant leavingtungsten carbide reduction die 38 generally in the form of a very thinclose coating continuous along and around the reduced wire 13:: whichgives it a relatively dark matte finish appearance in the case ofaluminum clad steel. Successive such die reduc tion steps may beperformed, except that no additional carrier dabbing or wiping normallyis desired, on a continuous multihole machine with each of suchreduction steps representing as much as one B & S draft at practicalwire drawing speeds up to 400 feet per minute and over. In the case ofaluminum clad steel wire so drawn the thickness of the aluminum claddingmay represent a cross section in the amount of 20% or more of aluminumin the total cross sectional area of the clad wire. The lubricantcoating remaining on the wire may readily be removed by a vapordetergent bath or liquid acid cleaning.

Die drawing tests on aluminum clad steel wire at block speeds as high as400 feet per minute have shown that when the approach angle 52 of thedie 36 and the approach angle of the die 37 are from about 12 to 16,they are satisfactory. Further, the respective average radial clearancesfrom the bearings in those dies are preferably about 0.0025 inch and0.001 inch, representing an average radial distance from the outside ofthe clad wire to the Wall of the respective bearing portion. A diameterat the bearing in the pressure dies which is not more than 0.010 of aninch larger than the clad wire diameter appears to represent the maximumclearance tolerance for achievement of a suitable pressure extrusioneffect with such aluminum clad steel wire. In the case of the drawingdie 38, the preferable approach angle 53 should be about 6 with amaximum of about 12 when die 38 is the first reduction die, a somewhatlarger approach angle being tolerable in succeeding reduction steps whenthe clad wire carried the coating of lubricant thereon. All of the dieswere flared for relief on the exit side of their respective bearingportions. A carrier, dag No. 200 sold by Acheson Colloids Company, wasused just ahead of the first draft and the fine powder soap lubricantused was Standard Industrial Compound No. 55 XXX. And, the resistance tothe pulling of the clad wire being reduced appears to be taken up by thereduction die itself.

Various changes may be made in the illustrated embodiment, and otherembodiments and materials used, without departing from the spirit of ourinvention or the scope of the appended claims.

We claim:

1. In die drawing aluminous or the like clad ferrous or the like corerod or wire in which the cladding is a continuous, coherent covering ofappreciable thickness bonded to said core, the steps comprising, incombination, applying a tacky substance to said clad rod or wire,pulling it through a fine powder die drawing soap lubricant compatiblewith said cladding to picl; up a lubricant coating then pulling itthrough at least one pressure die having a bearing diameter slightlylarger than the diameter of said clad rod or wire to prevent countermovement of lubricant, then drawing it through a succeeding coaxialreduction die in sealed relation to the back of said pressure die andhaving a bearing diameter a draft amount less than the diameter of saidclad rod or wire, said dies defining a sealed space between said dies,maintaining a very high pressure of lubricant in said space by movementof said clad rod.or wire therethrough sufiicient to resist formation ofa progressively increasing transverse circumferential shoulder in saidcladding by said reduction die, and subjecting said clad rod or wire topressure caused by lubricant carried into said space by said clad rod orWire sufficient to force said cladding to pass through said reductiondie along with said core for drawing of said cladding uniformly withsaid core and to cover the drawn clad rod or wire during its reductionpassage through said reduction die with an enveloping thin layer oflubricant continuous along and around the same, said reduction diehaving its exit at much lower pressure than said firstnamed pressure,whereby proportionate reduction is provided in the cladding and core ofsaid clad rod or wire without stripping, scoring or upsetting saidcladding.

2. A die drawing device for a clad rod or wire having a softer metalcladding and a harder metal core, comprising, in combination, means forlubricating the surface of said clad rod or wire comprising means toapply powder soap lubricant to said clad rod or wire in advance of anypressure die, at least a pair of pressure dies each having a centralopening therethrough with a relatively straight-sided approach angle anda cylindrical bearing portion with a diameter slightly larger than thatof said clad rod or wire to pass lubricant therewith and preventcountermovement of said lubricant, said pair of such pressure dies beingin coaxial succession with the space between them also sealed to providean operative pressure space, a coaxial reduction die having a smallercentral opening therethrough with a generally narrow relativelystraight-sided approach angle not to exceed in the neighborhood of fromabout 6 to about 12 and a cylindrical bearing portion, a sealing ringsubstantially in engagement with the rear face of the last pressure dieand the front face of said reduction die, said sealing ring having acentral opening to clear said clad rod or wire passing through from saidlast pressure die, said reduction die being operative substantially totake up the resistance to reduction offered by said clad rod or wire tobeing drawn, said dies and ring being in coaxial alignment and the spacefollowing said reduction die affording relief for the drawn clad rod andwire, and mounting means for holding said dies axially pressed togetherto seal the central opening spaces between them and to hold them rigidlyagainst longitudinal and transverse movement, said central opening spacebetween said last pressure die and said reduction die being operative toprovide a very high pressure chamber to force said cladding metal topass through said reduction die without upsetting and concurrently withsaid core metal with a continuous layer of lubricant on the surface ofsaid drawn clad rod or wire, whereby a clad rod or wire will carrylubricant into the space sealed by said sealing ring to provide a veryhigh pressure in said last-mentioned central opening space operative topromote uniform drawing of said cladding and core in said clad rod orwire by said reduction die.

References Cited in the file of this patent UNITED STATES PATENTS UNITEDSTATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,080,962March 12, 1963 Ernst Fleischmann et a1,

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 2, Times 12 and 13, for "comprised" read comprises line 45, after"in" insert the o Signed and sealed this 17th day of September 1963.-

(SEAL) Attest:

DAVID L. LADD Commissioner of Patents ERNEST W. SWIDER Attesting Officer

1. IN DIE DRAWING ALUMIOUS OR THE LIKE CLAD FERRROUS OR THE LIKE COREROD OR WIRE IN WHICH THE CLADDING IS A CONTINUOUS, COHERENT COVERING OFAPPRECIABBLE THICKNESS BONDED TO SAID CORE, THE STEPS COMPRISING, INCOMBINATION,, APPLYING A TACKY SUBSTANCE TO SAID CLAD ROD OR WIRE, PULL:ING IT THROUGH A FINE POWDER DIE DRAWING SOAP LUBIRCANT COMPATIBLE WITHSAID CLADDING TO PICK UP A LUBRICANT COATING THEN PULLING IT THROUGH ATLEAST ONE PRESSURE DIE HAVING A BEARING DIAMETER SLIGHTLY LARGER THANTHE DIAMETER OF SAID CLAD ROD OR WIRE TO PREVENT COUNTER MOVEMENT OFLUBRICANT, THEN DRAWING IT THROUGH A SUCCEEDING COAXIAL REDUCTION DIE INSEALED RELATION TO THE BACK OF SAID PRESSURE DIE AND HAVING A BEARINGDIAMETER A DRAFT AMOUNT LESS THAN THE DIAMETER OF SAID CLAD ROD OR WIRE,SAID DIES DEFINING A SEALED SPACE BETWEEN SAID DIES, MAINTAINING A VERYHIGH PRESSURE OF LUBRICANT IN SAID SPACE BY MOVEMENT OF SAID CLAD ROD ORWIRE THERETHROUGH SUFFICIENT TO RESIST FORMATION OF A PROGRESSIVELYINCREASING TRANSVERSE CIRCUMFERENTIAL SHOULDER IN SAID CLADDING BY SAIDREDUCTION DIE, SAID SUBJECTING SAID CLAD ROD OR WIRE TO PRESSURE CAUSEDBY LUBRICANT CARRIED INTO SAID SPACE BY SAID CLAD ROD OR WIRE SUFFICIENTTO FORCE SAID CLADDING TO PASS THROUGH SAID REDUCTION DIE ALONG WITHSAID CORE FOR DRAWING OF SAID CLADDING UNIFORMLY WITH SAID CORE AND TORECOVER THE DRAWN CLAD ROD OR WIRE DURING ITS REDUCTIION PASSAGE THROUGHSAID REDUCTION DIE WITH AN ENVELOPING THIN LAYER OF LUBRICANT CONTINUOUSALONG AND AROUND THE SAME, SAID REDUCTION DIE HAVING ITS EXIST AT MUCHLOWER PRESSURE THAN SAID FIRST NAMED PRESSURE, WHEREBY PROPORTIONATEREDUCTION IS PROVIDED IN THE CLADDING AND CORE OF SAID CLAD ROD OR WIREWITHOUT STRIPPING, SCORING OR UPSETTING SAID CALDDING.
 2. A DIE DRAWINGDEVICE FOR A CLAD ROD OR WIRE HAVING A SOFTER METAL CLADDING AND AHARDER METAL CORE, COMPRISING, IN COMBINATION, MEANS FOR LUBRICATING THESURFACE OF SAID CLAD ROD OR WIRE COMPRISING MEANS TO AAPPLY POWDER SAOPLUBRICANT TO SAID CLAD ROD OR WIRE IN ADVANCE OF ANY PRESSURE DIE, ATLEAST A PAIR OF PRESSURE DIES EACH HAVING A CENTRAL OPENING THERETHROUGHWITH A RELATIVELY STRAIGHT-SIDED APPROACH ANGLE AND A CULINDRICALBEARING PORTION WITH A DIAMETER SLIGHTLY LARGER THAN THAT OF SAID CLADROD OR WIRE TO PASS LUBRICANT THEREWITH AND PREVENT COUNTERMOVEMENT OFSAID LUBRICANT, SAID PAIR OF SUCH PRESSURE DIES BEING COAXIAL SUCCESSIONWITH THE SPACE BETWEEN THEM ALSO SEALED TO PROVIDE AN OPERATIVEPPRESSURE SPACE, A COAXIAL REDUCTION DIE HAVING A SMALLER CENTRALOPENING THERETHROUGH WITH A GENERALLY NARROW RELATIVELY STRAIGHT-SIDEDAPPROACH ANGLE NOT TO EXCEED IN THE NEIGHBORHOOD OF FROM ABOUT 6* TOABOUT 12* AND A CYLINDRICAL BEARING POTION, A SEALING RING SUBSTANTIALLYIN ENGAGEMENT WITH THE REAR FACE OF THE LAST PRESSURE DIE AND THE FRONTFACE OF SAID REDUCTION DIE, SAID SEALING RING HAVING A CENTRAL OPENINGTO CLAER SAID CLAD ROD OR WIRE PASSING THROUGH FROM SAID LAST PPRESSUREDIE, SAID REDUCTION DIE BEING OPERATIVE SUBSTANTIALLY TO TAKE UP THERESISTANCE TO REDUCTION OFFERED BY SAID CLAD ROD OR WIRE TO BEING DRAWN,SAID DIES AND RING BEING COAXIAL ALIGNMENT AND THE SPACE FOLLOWING SAIDREDUCTION DIE AFFORDING RELIEF TO THE DRAWN CLAD ROD AND WIRE, ANDMOUNTING MEANS FOR HOLDING SAID DIES AXIALLY PRESSED TOGETHER TO SEALTHE CENTRAL OPENING SPACES BETWEEN THEM AND TO HOLD THEM RIGIDLY AGAINSTLONGITUDINAL AND TRANSVERSE MOVEMENT, SAID CENTRAL OPENING SSPACEBETWEEN SAID LAST PRESSURE DIE AND SAID REDUCTION DIE BEING OPERATIVE TOPROVIDE A VERY HIGH PRESSURE CHAMBER TO FORCE SAID CLADDING METAL TOPASS THROUGH SAID REDUCTION DOE WITHOUT UPSETTING AND CONCURRENTLY WITHSAID CORE METAL WITH A CONTINUOUS LAYER OF LUBRICANT ON THE SURFACE OFSAID DRAWN CLAD ROD OR WIRE, WHEREBY A CLAD ROD OR WIRE WILL CARRYLUBRICANT INTO THE SPACE SEALED BY SAID SEALING RING TO PROVIDE A VERYHIGH PRESSURE IN SAID LAST-MENTIONED CENTRAL OPENING SPACE OPERATIVE TOPROMOTE UNIFORM DRAWING OF SAID CLADDING AND CORE IN SAID CLAD ROD ORWIRE BY SAID REDUCTION DIE.